Field of the Disclosure
The following relates generally to wireless communication, and more specifically to avoiding extended interframe space (EIFS) in a wireless local area network.
Description of Related Art
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power).
A wireless communications network may include a number of network devices such as access points (APs) that can support communication for a number of wireless devices. A wireless device may communicate with a network device bi-directionally. For example, in a wireless local area network (WLAN), a station (STA) may communicate with an associated AP via downlink and uplink. The downlink (or forward link) refers to the communication link from the AP to the station, and the uplink (or reverse link) refers to the communication link from the station to the AP.
In a WLAN, multiple stations may share wireless transmission resources using a contention based channel access procedure. In a contention based system, different stations may wait for different periods of time after the last successfully received frame before beginning to transmit. This time period may be known as a backoff counter. If a frame is received unsuccessfully, a station may wait for an additional time period, the EIFS, before continuing to decrement the backoff counter. The EIFS may allow another station time to send an acknowledgement (ACK) in response to the received frame if one is appropriate.
Whether or not a frame is received correctly depends on a number of factors including the rate at which the message is sent, and the distance between the sender and the receiver. Various stations may be located relative to each other in a manner such that some stations successfully receive a frame and other stations do not. If no ACK is sent, those stations that successfully receive the frame may begin the backoff immediately while those that receive a faulty frame check sequence (FCS) may wait for the EIFS. This may result in a biased access procedure.